docs: def get_conditions(self, service_id):
          """
          Build a Conditions XML block for a SAML 1.1 Assertion.
          """
          conditions = etree.Element('Conditions')
          conditions.set('NotBefore', self.instant())
          conditions.set('NotOnOrAfter', self.instant(offset=30))
          restriction = etree.SubElement(conditions, 'AudienceRestrictionCondition')
          audience = etree.SubElement(restriction, 'Audience')
          audience.text = service_id
          return conditions